Push-pull Strategy with Trap Crops, Neem and Nuclear Polyhedrosis Virus for Insecticide Resistance Management in Helicoverpa armigera (Hubner) in Cotton

A Regupathy,P Duraimurug

doi:10.3844/ajassp.2005.1042.1048

Abstract

Insecticide resistance in Helicoverpa armigera (Hubner) is a major threat to cotton production in India. The virus infection was found to increase the susceptibility of H. armigera to the insecticides. But, use of Nuclear Polyhedrosis Virus (NPV) on a larger scale and on cotton due to leaf alkalinity poses certain practical problems. Hence, studies were carried out to assess the effects of push-pull strategy with trap crops, neem and NPV in cotton for the management of insecticide resistant H. armigera. Field experiments were conducted on cotton (MCU5) with trap crops (okra and pigeonpea) and neem was used to diversify the pests to trap crops whereby the control of these pests was assessed with the application of NPV. The preference of H. armigera was towards okra and pigeonpea as a trap crop compared to cotton. Application of NSKE on cotton diversified the H. armigera towards untreated okra and pigeonpea. Push-pull strategy with the conjunctive use of trap crops, restricted application of NSKE on cotton leaving trap crops and restricted application of NPV on trap crops was highly effective in reducing the incidence of H. armigera and damage to fruiting bodies, boll, locule and inter locule basis over cotton sole crop (untreated check). The percent recovery of NPV infected larvae varied from 37.5-47.5, 32.8-39.2 and 14.2-20.2% on okra, pigeon pea and cotton respectively. The synthetic pyrethroids resistance in field survived H. armigera at the end of the season was reduced from 87.5-93.1% to 76.4-84.3%.

Highlights

The cotton bollworm Helicoverpa armigera (Hubner) referred to as American bollworm, gram pod borer, tomato fruit borer holds the first rank amongst agricultural pests of both tropical and temperate countries of the world attacking a number of foods, subsidiary and cash crops including ornamental and medicinal plants[1]
The prevalence of high level of resistance to synthetic pyrethroids indicates an urgent need for implementation of curative Insecticide Resistance Management (IRM) for H. armigera
The experiments were of F1 field population of H. armigera before first spray laid out in a randomized block design with three and F1 field survived population at the end of the crop variants viz., trap crops, Neem Seed to synthetic pyrethroids was monitored using Kernel Extract (NSKE5%) spray restricted on cotton Discriminating Dose (DD) assays and the percent (MCU5) leaving trap crops and HaNPV restricted on trap crops leaving cotton

Summary

Introduction

The cotton bollworm Helicoverpa armigera (Hubner) referred to as American bollworm, gram pod borer, tomato fruit borer holds the first rank amongst agricultural pests of both tropical and temperate countries of the world attacking a number of foods, subsidiary and cash crops including ornamental and medicinal plants[1]. In cotton sole crop (untreated check), the mean egg and larval population at two locations was in the range of 31.3 to 32.2 and 27.1 to 30.3 per ten plants respectively and percent damage was in the range of 30.3 to 30.9, 38.0 to 40.0, 27.0 to 35.0 and 11.2 to 11.6 on fruiting bodies, boll, locule and inter locule basis respectively.

Results

Conclusion